Screw-propeller for aeroplanes, airships, vessels, and the like.



Y 0.BRUNNBR. SCREW PROPELLER FOB ABROPLANES, AIRSHIPS, VESSELS, AND THELIKE.

I APPLIUATION FILED T11R16, 1913.

1, 1 05,753. Patented Aug. 4, 1914.

2 SHEETS-SHEET 1.

Fig. 5. A lA AK E 11 A o. BRUNNER. SCREW PROPELLER FOR AEROPLANES,AIRSHIPS, VESSELS, AND THE LIKE.

APPLIOATION FILED FEB. 16, 1913.

1,105,? 53. Patented Aug. 4, 1914.

2 SHEETS-SHEET 2.

3 hie/Mal.- 8 6 5; a W

OTTO BRUNNER, OF SAIMANNSLEHEN, AUSTRIA-HUNGARY.

SCREW-PROPELLER FQRAEROPLANES, AIRSHIPS, VESSELS, AND THE LIKE.

Specification of Letters Patent.

Patented Au". 4, 1914.

Application filed February 16, 1913. Serial No. 748,567.

To all whom it may] concern Be it knownthat I, OTTO BRUNNER, ofS:1imannslehen, Lower Austria, inthe Empire of Austria-Hungary, asubject of the Emperor'of Austria-Hungary, have invented certain new anduseful Improvements in and Relating to Screw-Propellers for Aeroplanes,Air-ships, Vessels, and tht like; and I do hereby declare the followingto bea full, clear, and exact description of the invention, such as willenable others skilled in the art to which it appertains to make and usethe same.

This invention relates to screw propellers for aeroplanes, airships,sea-goin vessels, and the like, and it has for its 0 ject theconstruction of screw propellers for these purposes based upon the ideaof forming that active part (hereinafter called the front part) of thevane surface which first im- 'nnges upon the surrounding medium, andwhich is, in the sense of rotation of the vane, on the front sidethereof, in such mannor that substantially all the particles of thesurrounding medium impinging upon it are reflected or diverted in acertain manner into the immediate proximity of another part (hereinaftercalled the rear part) of the active vane surface, whereby a condensationof the medium is produced at the rear part so that the rear part movesin a denser medium and has its effect increased. However, the front andrear arts are formed so that they uirect the partlcles of the medium ascompletely as possible against a peripherally added surface (hereinaftercalled the peripheral. part) with a projection directed backwardrelatively to the direction. of movement, to thereby cause also .acondensation of the medium and thereby increase the action of the screw.It has been found by experiments that these conditions are met by ascrew propeller wherein the front part of its vane or vanes consists ofa conoidal surface, having its apex in the axis 'of the screw, havingits generating line formed by a cycloid segment, and having its leadingline formed by an arm.of a parabola opening inthe direction of movement,the axis of the parabola being situated in the plane of rotation, thatis, in a plane perpendicular tothe axis of the screw, and a screw exitsurface, forming the rear part, which is generated by the movement ofthe cycloid segment along the axis of the screw and along a lineextending obliquely backward,

.t icles 0 being connected to the conoidal surface. Preferably, a vaneprojection, rounded off peripherally backward and arranged on the outeror peripheral part of the vane, extends in a direction opposite to thatof the rotation of the propeller. Vane projections have been usedheretofore, but in the present case the vane projection has an addedfunction in that the condensed medium sliding along the cycloid segmentis pressed under it, whereby an increased upward movement or forwardmovement is obtained.

In order that this invention may be better understood, I now proceed todescribe it with reference to the accompanying drawings illustrating aconstructional form of a vane for a propeller, in which- Figure 1represents an elevation of a vane for a sea-going vessel; Fig. 2represents a plane of the active surface of the vane of Fig. 1, showingalso several cross sections of the vane taken at different points; Fig.3 represents a side elevation of the vane of Fig. 1; Fig. 4 represents awell known method of constructing a cycloid by rolling a circle along astraight line; Figs. 5, 6, 7 and 8 are similar to Figs. 1,2, 3 and 4,but illustrate the constructional form of a vane for an airship.

The hub L, which is connected to a driving shaft (not shown) driven byany suitable source of power such as an internal combustion engine, isprovided with a suitable number of vanes. The construction of the activesurfaces of these vanes constitutes the sub'ect matter of the presentinvention, thebac side of the vanes being formed in any convenientmanner and not being a part center to the periphery of the vane in theshape of a cycloid in order that those particles pushing on the vanenear the center thereof are led as quickly as possible toward the perihcral part. Furthermore all part the medium impinging upon the frontpart of the vane should be reflected in such manner as to obtain acondensation of the medium where the rear or exit part of the vane acts.Now, it is well known that a focus of the parabola.

' surface having a cross section in the form of aparabola reflects allparticles which move parallel to the axis of the parabola and whichcontact with the surface toward the Thus, I make the cross sectionjofthe front part of the active surface of the vane inthe form of an armthere is placed therein a cycloid B D (Figs.

of a parabola, whereby when the vane r0- tates' all particles of themedium impinging upon-'that'f'ront part are reflected in the mannerhereinbefore described.

In accordance with my invention, the active surface of the vane may beformed as follows,' reference being had to Figs. 1 to 4 for thepropeller vane of a sea-going'vessel, and to F igs. 5 to 8 for apropeller vane of anairship; assume that a horizontal plane A .A ispassed through the vane and that 2 or 6) which has one point coincidentwith thecenterof the hub'L and which has been formed by rolling a circleof radius B C (Figs, 4 or 8) along a straight line. Upon rotating theline B D about the center B (Figs. 2 or 6), each point of the line B Ddescribes a circle. Thus the point E de scribes the circle E Z having aradius E B. This circle represents the section of a vertical cylinder ofradius E B cut by the horizontal plane A A. Suppose now that. a

parabola.- having the point F on its arm be constructed ;in a verticalplane, the vertex of the parabola being at E and the axis being in thehorizontal plane and forming a tangent to the circle; and furthersuppose that the plane of the parabola is bent in such a way that'the'parabola falls'into the surface'of the vertical cylinder whose base is EZ. The point F will be displaced thereby to the point F. If now t1 ecycloid E is moved, its point .E traveling a ion the parabola E F andits point B being xed at the center of the arm, a conoidal surface willbe produced, and the generating ,line of this conoidal surface is thecycloid segment, while the leading line of the conoidal surface is theline E F of the parabola which opens in the directionof rotation of thevane.

1 B H and B E,- respectively,

If vertical cylinders havin from the vertical position into thehorizon-- tal position along the lines G 1",H K, and E F, respectively.

The rear part of the active vane surface is generated by moving thecycloid segment B E with its free end along a line E M which leads fromthe point. E obliquely backward, whereby a screw surface is obtained.The lines G N, H O and E P are .the lines of intersection with thevertical cylinders above mentioned after flattening and turningthemdown. In order to have asurface which is entirely. smooth and withoutany line of fracture or any reentering line, the front part of the vaneis suitably curved out near the line of juncture with the rear part,as-shownin Figs. 2 and 6. The lines of intersection with the verticalcylinders may be, for instance, I Q, N", K O and F R P, respectively.

To the front and rear parts of the vane,

there is annexed peripherally the third orperipheral part'having towardits rear, in the sense of movement of the vane, as 1nd1- cated by thearrow in Figs. 2 and 6, a vane projection rounded :off peripherallybackward. The active surface of that part of the. vane is more or less aplane, and is gen.- erated by gradually flattening the curved front partof the vane. The plane of intersection of this part with a cylinder ofra- I 'dius B .S flattened or stretched out, and

turned down at a right-angle in the. same manner as described inconnection with the front and rear parts of the vane, presents trated inFigs. 2and 6, the plane corresponding to the active surface being T U,and the backside being T D U.

If the screw 'propeller shown in Figs. 1 to 4 or Figs. 5 to 8 be turnedin the direction of the medium impinging upon the co-noidalsurface'parallel to the ax'is'of the parabola forming its base arereflected to the line of the foci W. This medium is condensed there, sothat the screw surface moves in a 'condensed medium, its forward orupward driving action thereby being increased. Simulthe shape of aplano-convex lens, as illus the arrow of Figs. 2 or 6, all particles oftaneously, however, the particles of the -medium are for the'most partpushed away against the vane projection D U" U, in consequence of the ccloidal form'of the generatin line formlng the shortest path, wherebythe action of this part of the. vane is increased-also. I

In the foregoing, the of theyanes have been described separately forthesake in general all of these parts may be made of one piece of wood ormetal. The vane may '120 of clearness, but it will be'understoodthatconsist of wood or metal, and the backside thereof may be formed inany suitable manner. The shape of the cycloid, as well as the form ofthe parabola, is dependent upon the medium in which the vane istorotate, and is also dependent upon the predetermined speed and of thematerial of the vane, all of which may be easily determined byexperiments. In applying the invention to screw propellers for sea goingvessels, the thickness of the vane, that is, the distance betweenopposite points on the active surface and bachside of the vane, shouldgenerally be greater than in the case of vanes for airships.

Experiments have shown that a 501' 1w propeller constructed inaccordance with my invention produces an upward or forward action,approximately 30% greater than that of a screw propeller constructedaccording to the Ressel system.

Il'ai lug thus described my invention, what I claim is:

1. In avane for screw propellers, a front part having an active surface,and a rear part ha ving an active surface, the active surface of thefront part being shaped to reflect substantially all the particles ofthe impinging medium into innnediate proximity to the active surfaceofthe rear part; substantially as described.

2. In a vane for screw propellers, a front part having an activesurface, a rear part having an active surface, and a peripheral partformed peripherally of said parts, the active surface of the front partbeing shaped to reflect substantially all of the particles of theimpinging medium into immediate proximity to the active "surface of therear part, and the active surfacesof the front and rear parts beingshaped to direct the particles of the impinging medium against theactive surface of the peripheral part; substantially as described.

3. In a vane for screw propellers, a front part having an activesurface,-a rear part having an active surface, and a peripheral partformed peripherally ofsai d parts and having a projection extending in adirection oppositev to that of the movement of the vane, the activesurface of the front part being shaped to reflect substantially all ofthe particles of the impinging medium into immediate proximity to theactive surface of the rear part, and the active surfaces of the frontand rear parts being shaped to direct the particles of the mediumagainst the active surface of the peripheral par-t; substantially asdescribed.

-l. In a vane for screw propellers, a front part having an activesurface of eonoidal form. with its apex in the axis of rotation of thepropeller and its generating line formed by a hyeloid segment and itsleading line formed i an arm of a parabola open in the direction ofmovement and having its axis in the plane of rotation of the ante, and arear part adjoining the front part and consisting of a screw surface forthe exit of the impinging medium; substantially as described.

In a vane for screw propellers, a front part having an active surface ofeonoidal form with its apex in the axis of rotation of the propeller andits generating line formed by a cycloid segment and its leading lineformed by an arm of a parabola open in the direction of movement andhaving its axis in the plane of rotation of the vane, and a rear partadjoining the front part and having a screw active surface for the exitof the impinging medium, said screw surface being formed by the movementof the c cloid segment along the axis of the propeller and along a lineextending obliquely and in a direction opposite to that of the movementof the vane; substantially as described.

.6. In a vane for screw propellers. a front part having an activesurface of eonoidal form with its apex in the axis of rotation of thepropeller and its gcne'ating line formed by a cycloid segment and aleading line formed by an arm of a parabola open in the direction ofmovement and having its axis in the plane of rotation of the vane, arear part adjoining the front part and having a screw active surface forthe exit; of the im inging medium, said screw surface being fhrmed bythe movement of the c vcloid segment along the axis of the parabola andalong a line extending obliquely in a direction opposite to that of themovement of the vane, and a peripheral part added p1- ripherally to thefront and rear parts and having a projection extending rearwardlyrelatively to the direction of movement of the vane, the peripheral partbeing rounded off peripherally; substantially as described.

In testimony whereof I affix my signature, in presence oftwo witnesses.

OTTO BRUNNER.

Witnesses:

JOIIANN Lox, Atons'r FUcoi-ni.

It is herebyeertified that in Letters Patent No. 1,105,753, grantedAugust 4, 1914,

upon the application of Otto Brunner, of Saimannslehen, Austria-Hungary,for an improvement in Screw-Propellers forAeroplanes, Airships, Vessels,and the Like,

an error appears in the printed-specification requiring correetionesfollows: Page 2,

line 14, for theword'and reference letter eycloid E? read cyclm'd E F;and that the said Letters Patent should be read with this correctiontherein that thesame may conform to the record of the case in the PatentOflice.

Signed and sealed this 29th day of September, A. D., 1914.

v [SEAL] R. F. WHITEHEAD,

Act'i/ng Commissioner of Patents.

